Wont start after fixing air leak in fueling...?

Discussion in 'VW Mk3 Jetta, Passat TDI and other/older diesels' started by dubste2, Jan 24, 2010.

  1. dubste2

    dubste2 New Member

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    Hi guys,

    I have a 1994 passat 1z,

    It wouldnt start and there was clearly air in the fuel lines.
    I disconnected the battery and put a charged one in.
    I removed the air filter to find that it had worn a hole through the fuel line!
    I cut it out and sorted it all out.
    I turned the engine over and now there is no air in the clear pipes whatsoever.
    I had the injectors cracked off to bleed, but only a small ammount of fuel would get to them.
    I thought it would come out pretty fast, and almost hit the bonnet but it didnt.

    I cannot get it started unless i use ether/easy start, but then when this dies out it doesnt continue to run. It also doesnt help the engine to suck the fuel to the injectors.

    Does anybody have any opinions on this? could it be the solenoid on the end of the pump not letting fuel through? i can hear it click when i turn the ignition on though.

    Any help will be greatfully appreciated,

    Scott
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  2. chittychittybangbang

    chittychittybangbang Administrator

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    If you hear it click it's probably not the fuel shut off solenoid. I don't know if they had this relay in the 1994 but since you said 1z engine I'll bet it does have a relay 109. If you don't see the glow plug light come on then this is the cause. If you do, crack two fuel hard line at the fuel injectors a tiny bit more and see if more fuel comes out. A rag should be very wet with fuel. The other 2 should be snug to give fuel to the engine. Make sure the fuel filter lines are not backwards.
  3. buzybee

    buzybee New Member

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    are the glow plugs working
  4. dubste2

    dubste2 New Member

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    hi guys, thanks for the replys.

    The glow plug relay is 103(when i take that one out the glow plugs light doesnt come on)...? Its grey too, but not 109. It was making funny noises when the battery was almost dead but now the battery is good it doesnt do this it seems fine.
    How do i find out if the glow plugs are working?

    I think the problem may be no/little fuel from the injection pump, as if its not opened to send fuel through the solid lines to the injectors.
    Could this be checked/overcome with vagcom? or does it need to run to use that?

    So i should crack two lines a little, any preferences? 1,2/3,4? i know the 3rd has that sensor on it/its taller, does this one need to be cracked off a little?

    So could there be a fuel shut off relay/solenoid? i can hear the relays inside the car click etc, but if i get someone else to turn the key i can hear a click from the solenoid on the end of the fuel pump.

    P.S the fuel filter is brand new and theres is now no air in the lines at all on the clear plastic line side of the pump.
    Thanks alot for your help guys
  5. chittychittybangbang

    chittychittybangbang Administrator

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    Again, I don't know if the 1994 engine is exactly the same and I think the electronics are slightly different.

    The relay 109 on later cars was originally grey and can fail. If your glow plug light does not come on at all when you start and the GP relay is in place, it's probably relay 109. This controls power to the ECU. No ECU, no fuel injection. I suggest not cracking open fuel line #3 to avoid damaging the sensor. Also, make sure to counterhold each injector when loosening the union. If you hear the click at the fuel shut off solenoid when you turn the key, it's probably good.
  6. dubste2

    dubste2 New Member

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    ok well my glow plug light seem to be working ok.
    Im going to loosen fuel line 1 and 2 and see what the results are.

    Do you know what will happen if i put a 12v live to the solenoid on the pump will this bypass the ecu and let the fuel through to the injectors? or just do nothing?

    Thanks for the comments mate
  7. chittychittybangbang

    chittychittybangbang Administrator

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  8. dubste2

    dubste2 New Member

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    Hmmmmmm, had no luck today.

    Took the solenoid off the second pump i had and it seemed louder than the other one when clicking on and off but still no fuel at the injectors.
    Only a tiny tiny tiny bit.

    I was told that if i get a tow and bump start the car it could possibly pull the fuel through...?

    I put vag com on it and it only came up with the code for the fuel shut off solenoid, think this was because i put a 12v feed to it. I cleared it and checked again and now there is no codes.

    Only thing i could see is that in the erm? values section the injector was set at 3.1degrees ATDC... is that after top dead center? it said it should be between 2 and -2 or -3 i think.

    If the glow plugs are/are not working how does this effect the fuel from the pump?
    Its just not coming to the injectors from the end of the pump!

    Might have to take it to a garage its doing my head in lol
  9. JoeMA

    JoeMA New Member

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    I'm pretty sure it should at least sound like it's going to start if you are getting fuel but bad glow plugs. I wouldn't bump start it because if you're not getting fuel now, you won't get fuel when someone pulls the car. There must be something wrong with the pump or fuel filter, or fuel pickup, or fuel lines, maybe a fuel line got pinched or the timing belt is wrong? Is this a new pump? If you opened the line and didn't get fuel it must be a pump or at least fuel related problem.
  10. dubste2

    dubste2 New Member

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    well theres fuel coming out of the return line and theres no air in it. It just doesnt seem to want to go up the four steel pipes from the pump to the injectors...

    I would say its primed.
    If the timing is wrong wouldnt it still come out of the steel lines?

    cheers bud
  11. chittychittybangbang

    chittychittybangbang Administrator

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    It really just sounds like the injection pump is not giving fuel which might be traced to the ECU or wiring. The injectors work on fuel pressure so you are getting fuel. The question is why?
  12. dubste2

    dubste2 New Member

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    Thanks for the reply.

    So next thing is to check all the connections to the pump then?

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